1. Field of the Invention
The present invention relates to a control system for controlling a target device having an influence on safety of maintenance work, and a terminal device for maintenance worker and a control device included in the control system.
Priority is claimed on Japanese Patent Application No. 2011-002943, filed Jan. 11, 2011, the content of which is incorporated herein by reference.
2. Description of Related Art
In maintenance work, safety measures, such as a measure for prohibiting entry into a transportation facility during maintenance work for a transportation system or a measure for prohibiting use of an elevator during maintenance work for an elevator system, are executed using a remote manipulation in order to secure safety of workers (maintenance workers).
For example, in a rail transportation system, maintenance work for devices installed in a railroad line area that is a train traveling area may be executed. In this case, a measure for securing the safety of workers is executed by an ordering person in an operation control center. Such a measure includes, for example, stop of power supply to equipment to which electrical power is supplied, such as wires, protection from entry of a train (entry prohibition) using control of signaling equipment, and a deceleration instruction for an opposite railroad line.
Further, a manhole opening and closing switch provided in a manhole that is an entrance of a machine room of a passenger conveyor apparatus (e.g., an escalator) is disclosed in Japanese Patent Application, First Publication No. 2008-1467. When the open manhole is detected by the opening and closing switch, the passenger conveyor apparatus does not accept a remote manipulation. Accordingly, start-up by a remote manipulation can be suppressed.
However, the safety measure by a remote manipulation as described above may cause the workers to have anxiety and to be in danger.
For example, in the rail transportation system, the workers may be in danger due to erroneous situation recognition or manipulation mistake of an ordering person in an operation control center, even if workers are performing maintenance work inside the railroad line area. That is, the safety measure may not be executed or an executed safety measure may be released. Further, the worker at a maintenance worksite may not directly confirm an execution situation of the safety measure. In this case, the worker may feel anxious about whether the safety measure has been executed or not.
On the other hand, a worker confirming an execution situation of a safety measure or performing execution and release of the safety measure may be considered. This prevents the worker from feeling anxious and being in danger. However, for a certain work target, the worker may not be allowed to confirm the execution situation of the safety measure or to perform execution and release of the safety measure or it may be inappropriate for the worker to perform the execution and release of the safety measure.
For example, in a rail transportation system, a measure for stopping power supply to power supply equipment such as the above-described wires may be executed. For this measure, a worker needs to move to a substation, turn a breaker off, and perform a manipulation, for example, to apply a string indicating manipulation prohibition to the breaker. Further, a measure such as protection from vehicle entry (entry prohibition) or a deceleration instruction may be executed by controlling signaling equipment as described above. For this measure, the worker needs to move to a signaling control room, perform a manipulation for changing a signal from a manipulation panel, and perform a manipulation, for example, to apply a string indicating prohibition of release of a changing manipulation using the manipulation panel. Thus, the worker needs to move to a device control room (e.g. the substation or the signaling control room) and perform a manipulation for executing the safety measure. However, such a movement is limited to a case in which the device control room is in the vicinity of the worksite. Further, when the worker is not familiar with a manipulation for executing the safety measure, the worker may be in danger due to his or her manipulation mistake.
Further, according to a technique disclosed in Japanese Patent Application, First Publication No. 2008-1467, malfunction (start-up) caused by a remote manipulation can be suppressed as described above. Therefore, it is possible to prevent the worker from becoming anxious due to erroneous situation recognition or a manipulation mistake of a person performing the remote manipulation and to prevent the worker from being in danger.
However, in the technique described in Japanese Patent Application, First Publication No. 2008-1467, a physical switch is provided in the vicinity of the worksite to block a remote manipulation. In the rail transportation system, there are a plurality of worksites in a wide region. In such a case, in order for the worker to block the remote manipulation at the worksite by providing the switch for blocking a remote manipulation, a great number of switches must be provided. Accordingly, the cost for installing and maintaining the switches is expensive. Further, when the worker forgets to manipulate of the switch after work ends, the remote manipulation cannot be performed. Thus, it may be practically impossible to appropriately operate a remote manipulation by appropriately managing and operating a great number of switches.
Thus, for a system having a plurality of worksites in a wide region, it is not realistic to apply a method of providing the switches for blocking the remote manipulation in the vicinity of the worksites, such as the technique described in Japanese Patent Application, First Publication No. 2008-1467.